Effect of RR segment duration on short-term HRV assessment using Poincare plot

HRV analysis is an unprecedented tool capable of providing relevant information on autonomic modulation of sinus node as well as on diagnosis and prognosis in a variety of clinical conditions. Spectral analysis of the RR tachogram is typically used to estimate the effect of the sympathetic and parasympathetic modulation of the RR-intervals. An emerging analysis technique is the Poincare plot, the graphical representation of the correlation between consecutive RR intervals, which takes a sequence of intervals and plots each interval against the following interval. Keeping in view, its advantages like visual assessment; ability to display nonlinear aspects and complexity; no need of RR interval pre-processing; less sensitive to artifacts etc., the quantification of Poincare plot has been discussed recently for a better description of results. Previously, Poincare plot based HRV analysis has been reported for few minutes to several hours of RR segment durations. The major advantage of the Poincare plots lies in their relative insensitivity to artefacts and ectopic beats, while the major disadvantage is the need for a reasonable number of RR intervals and a longer ECG recording. To contain the nonstationarity and noise in long-term ECG records, short-term HRV analysis has been favoured. Here a study on a standard database containing nonhomogeneous group of subjects, has been carried out and 5-minute RR segment length has been shown to provide good enough plot morphology for visual evaluation. As the existing Poincare plot quantification measures are linearly related with the statistical measures, so the plot morphology alone should be considered for the assessment of autonomic and cardiovascular systems.